Outcome of allogeneic transplantation in newly diagnosed and relapsed/refractory multiple myeloma: long‐term follow‐up in a single institution

Allogeneic stem cell transplantation (allo‐SCT) has the potential to induce long‐term remission in multiple myeloma (MM), but the role of allo‐SCT in MM is controversial due to the high rate of treatment‐related mortality (TRM). However, although proteasome inhibitors and immunomodulatory drugs have improved the outcome of patients with MM, high‐risk patients still have a very poor prognosis. This indicates the need for new treatment strategies and identification of patients who might benefit from allo‐SCT. We therefore analyzed the outcome of one hundred and forty‐seven patients with MM who received an allo‐SCT at our institution (58 in first line, 89 in relapsed/refractory setting) after a median follow‐up of 88.8 months. For the first‐line setting, median progression‐free survival (PFS) and overall survival (OS) were remarkably good, with a CR rate of 48.3%, median PFS of 30.2 months, and 10‐yr OS of 51%. We found no difference in outcome for patients with high‐risk metaphase cytogenetics or FISH del(13q14), but efficacy in current standard high‐risk patients could not be determined. The outcome in the relapsed/refractory setting was poor, especially in the subgroup of patients relapsing within 18 months after auto‐SCT. Therefore, if applied at all in these patients, improvement of allo‐SCT is needed, focusing on reduction of TRM and more effective immunotherapy.